With rapid development of a display device such as a Thin Film Transistor-Liquid Crystal Display (TFT-LCD), requirements on various performances of the TFT-LCD are getting higher and higher. At present, as shown in FIG. 1, a gate electrode 12, a gate insulating layer 13, a semiconductor layer 17, an Indium Tin Oxide (ITO) layer 14 and a source-drain electrode layer are sequentially formed on a glass substrate 11, and the source-drain electrode layer is etched by using a photoresist pattern 18 by an etching process to form a source electrode 16 and a drain electrode 15, wherein, at this moment, the source electrode 16 and the drain electrode 15 are structures after the source-drain electrode layer is etched by using the photoresist pattern 18.
As shown in FIG. 2, next, when the semiconductor layer 17 is etched by using the photoresist pattern 18 to form a channel 19, due to blocking of an outer edge of the photoresist pattern 18, when plasma bombards the ITO, a part of indium-containing material 20 is remained on both sides of the source electrode 16 and the drain electrode 15, resulting in poor quality of the TFT-LCD; moreover, due to blocking of an inner edge of the photoresist pattern 18, a width of the channel 19 formed by etching the semiconductor layer 17 is less than a distance between the source electrode 16 and the drain electrode 15, that is, there is a semiconductor step, resulting in high leakage current.